I work with a small team of independent software developers. Each of us signed a “Work For Hire” contract with a customer. The customer paid us for the first three months, then failed for pay for the final three months. At this point, who owns this software?

Work for hire doctrine: A customer owns the software. The customer failed to compensate you, breaching your contract. Depending upon how much money is involved, you might want to talk to an attorney to evaluate whether it is worth going forward filing a complaint in a court of law unless you proceed pro se.

You need to talk to a labor and employment attorney regarding breach of contract. 30 min free consultation available?

Software "ownership" is a bit more complex than Biopico's analysis would have you believe.

First, it is unclear whether "work for hire" by written agreement would apply in your case. Depending on how the contract is drafted, and on other factors, the customer may have a license in the software nonetheless.

Second, assuming you retain copyright authorship (which is different than "ownership"), you might have some practical rights in the software from a business perspective.

Finally, I'm not sure where Biopico gets the "labor and employment attorney" from, but he's wrong. Any qualified litigator can handle breach of contract matters, although you'll likely want one who's well versed in intellectual property as well.

The developer here appears to be a contractor rather than an employee. Once that threshold issue is resolved the remaining issues appear to be a garden variety service contract overlayed with copyright related issues. You really don't need an employment specialist here.